Patent GB-827195-A (GB)
Title: Improvements in or relating to method and apparatus for modifying the surfaces of polyethylene films
Inventor: LOUKOMSKY SERGE ALEXANDER
IPC: B29C59/08
Filed: 1956-05-28
Abstract: Apparatus for superficially oxidizing polyethylene films by flaming them comprises a liquid-cooled member having a surface for supporting the film, means for drawing the film continuously over the surface in sliding contact therewith, the supporting member having a lip or trailing edge from which the film leaves the member, a gas burner nozzle having an elongated orifice transversely disposed relative to the path of the film over the surface for directing a flame against a part of the surface of the moving film which has ceased to be in contact with the supporting surface and is still adjacent to the lip or trailing edge, and means for supplying and removing cooling liquid to and from the supporting member to cool the supporting surface and lip of the member.  As shown in Fig. 1, collapsed polyethylene tubing T is fed from a supply roll 1 over a guide roller 2 and then over the curved surface 11 (Figs. 1, 2 and 5) of a circularly arcuate shoe 10, from the lip 10a of which the film is led through flame 41 at the top of the burner 9 to the roller 3.  From the roller 3 the film is led over the reversing roller 4 to the second of the flaming devices 8, by means of which the other side of the film is treated, and thereafter over the guide rollers 5, 6 to the wind-up roller 7.  The shoe 10 is secured at its ends by bolts 12 (Figs. 2 and 3) to spaced spaced vertical frame plates 13.  Adjacent the trailing edge 10a (Fig. 5) the shoe 10 has a transverse groove 14 in which a tube 15 is secured in good heat transfer relationship. Inlet and outlet ends of the tube 15 are connected to supply and exhaust lines 16, 17 <PICT:0827195/IV (a)/1> <PICT:0827195/IV (a)/2> <PICT:0827195/IV (a)/3> <PICT:0827195/IV (a)/4> <PICT:0827195/IV (a)/5> (Fig. 2) for cooling fluid to control th temperature of the shoe 10.  The nozzle 9 of each flaming unit 8 includes a pair of plates 18, 19 (Fig. 5) which are secured in face-to-face relationship by screws 20 (Figs. 2 and 4).  The contiguous straight upper edges 18a, 19a of the plates (Fig. 5) define an elongated burner nozzle orifice 22 which is disposed transversely of the path of travel of the film throughout its entire width adjacent to the lip or edge 10a from which the film leaves the shoe 10.  Ribs 23 (Figs. 2 and 5) having tapered ends 24, project inwardly from the plate 18 at regularly-spaced intervals and are held in engagement with the plate 19 by two rows of the screws 20, so that the orifice 22 has a predetermined width throughout the entire length of the nozzle 9.  A combustible mixture of a gaseous fuel and air is supplied to the nozzle 9 through a coupling 28 (Fig. 2) and three supply tubes 27 into a manifold chamber 26 (Fig. 5) which extends the length of the nozzle 9 and is formed by the plate 18 and a pressed-out concavity in the plate 19.  The nozzle 9 is provided with metal tubes 30, 31 secured in good heat-exchange relationship to the plates 18, 19 (Figs. 2 and 5), and a cooling liquid is passed through the tubes at a regulated rate in order to prevent overheating of the plates 18, 19.  The nozzle 9 includes end members 32 (Figs. 2, 3 and 4) secured to the ends of the plates 18, 19 and is adjustably supported by these end members on the mounting plates 13 of the frame F by adjustment bars 33 which are pivotally secured at their upper ends by pins 34 to the top centre of the mounting-plates 13.  The lower ends of the adjustment bars 33 are secured to the plates 13 by thumb-screws 35 which extend through arcuately slotted apertures 36 and provide for angularly adjusting the bars 33 and the nozzle 9 on the pins 34.  The position of the nozzle 9 may be vertically adjusted by means of thumbscrews 37 which extend through longitudinal slots in the bars 33 and through spacers 38 into threaded engagement with the end members 32, and pins 39 secured in the members 32 and projecting through the upper longitudinal slots 40 in the bars 33. Generally, the nozzle 9 is adjusted so that its orifice 22 is very close to the shoe lip 10a from which the film leaves the shoe 10.  The proximity of the nozzle orifice 22 to the lip 10a of the shoe 10 ensures the creation of a partial vacuum at the portion of the film surface between the lip 10a and the flame 41 and thereby cause the flame to be intensively directed on to this portion of the film surface.  Inks, cements and adhesives adhere more readily to the surfaces of films treated as described above.